Ultrathin, solution phase electrochromic devices

ABSTRACT

An electrochromic device includes a chamber defined by a substantially transparent first substrate, a second substrate, and a sealing member; wherein: the first substrate comprises a first surface, and a second surface comprising a first substantially transparent, electrically conductive coating and disposed opposite to the first surface; the second substrate comprising a first surface comprising a second substantially transparent, electrically conductive coating, and a second surface disposed opposite to the first surface; the second surface of the first substrate and the first surface of the second substrate being located proximally to each other and having a substantially uniform spacing of distance, d, between them; and 0 μm&lt;d≦65 μm; an electrochromic medium comprising a cathodic component, an anodic component, and a solvent; and insoluble spacing objects within the chamber, the insoluble spacing objects having a largest dimension that is greater than 0, but less than or equal to d.

CROSS-REFERENCE TO RELATED APPLICATIONS

This application claims the benefit of U.S. Provisional PatentApplication No. 62/371,495, filed on Aug. 5, 2016, the contents of whichare incorporated herein by reference in their entirety for any and allpurposes.

FIELD

The present technology is generally related to electrochromic devices.More particularly, it is related to ultrathin solution phaseelectrochromic devices.

SUMMARY

In one aspect, an electrochromic device is provided including a chamberdefined by a substantially transparent first substrate, a secondsubstrate, and a sealing member; wherein: the first substrate comprisesa first surface, and a second surface comprising a first substantiallytransparent, electrically conductive coating and disposed opposite tothe first surface; the second substrate comprising a first surfacecomprising an electrically conductive coating, and a second surfacedisposed opposite to the first surface; the second surface of the firstsubstrate and the first surface of the second substrate being locatedproximally to each other and having a substantially uniform spacing ofdistance, d, between them; and 0 μm<d≦65 μm; an electrochromic mediumcomprising a cathodic component, an anodic component, and a solvent; andinsoluble spacing objects within the chamber, the insoluble spacingobjects having a largest dimension that is greater than 0, but less thanor equal to d.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a cross-sectional schematic representation of anelectrochromic device, according to one embodiment.

DETAILED DESCRIPTION

Various embodiments are described hereinafter. It should be noted thatthe specific embodiments are not intended as an exhaustive descriptionor as a limitation to the broader aspects discussed herein. One aspectdescribed in conjunction with a particular embodiment is not necessarilylimited to that embodiment and can be practiced with any otherembodiment(s).

As used herein, “about” will be understood by persons of ordinary skillin the art and will vary to some extent depending upon the context inwhich it is used. If there are uses of the term which are not clear topersons of ordinary skill in the art, given the context in which it isused, “about” will mean up to plus or minus 10% of the particular term.

The use of the terms “a” and “an” and “the” and similar referents in thecontext of describing the elements (especially in the context of thefollowing claims) are to be construed to cover both the singular and theplural, unless otherwise indicated herein or clearly contradicted bycontext. Recitation of ranges of values herein are merely intended toserve as a shorthand method of referring individually to each separatevalue falling within the range, unless otherwise indicated herein, andeach separate value is incorporated into the specification as if it wereindividually recited herein. All methods described herein can beperformed in any suitable order unless otherwise indicated herein orotherwise clearly contradicted by context. The use of any and allexamples, or exemplary language (e.g., “such as”) provided herein, isintended merely to better illuminate the embodiments and does not pose alimitation on the scope of the claims unless otherwise stated. Nolanguage in the specification should be construed as indicating anynon-claimed element as essential.

In general, “substituted” refers to an alkyl, alkenyl, alkynyl, aryl, orether group, as defined below (e.g., an alkyl group) in which one ormore bonds to a hydrogen atom contained therein are replaced by a bondto non-hydrogen or non-carbon atoms. Substituted groups also includegroups in which one or more bonds to a carbon(s) or hydrogen(s) atom arereplaced by one or more bonds, including double or triple bonds, to aheteroatom. Thus, a substituted group will be substituted with one ormore substituents, unless otherwise specified. In some embodiments, asubstituted group is substituted with 1, 2, 3, 4, 5, or 6 substituents.Examples of substituent groups include: halogens (i.e., F, Cl, Br, andI); hydroxyls; alkoxy, alkenoxy, alkynoxy, aryloxy, aralkyloxy,heterocyclyloxy, and heterocyclylalkoxy groups; carbonyls (oxo);carboxyls; esters; urethanes; oximes; hydroxylamines; alkoxyamines;aralkoxyamines; thiols; sulfides; sulfoxides; sulfones; sulfonyls;sulfonamides; amines; N-oxides; hydrazines; hydrazides; hydrazones;azides; amides; ureas; amidines; guanidines; enamines; imides;isocyanates; isothiocyanates; cyanates; thiocyanates; imines; nitrogroups; nitriles (i.e., CN); and the like.

As used herein, “alkyl” groups include straight chain and branched alkylgroups having from 1 to about 20 carbon atoms, and typically from 1 to12 carbons or, in some embodiments, from 1 to 8 carbon atoms. Asemployed herein, “alkyl groups” include cycloalkyl groups as definedbelow. Alkyl groups may be substituted or unsubstituted. Examples ofstraight chain alkyl groups include methyl, ethyl, n-propyl, n-butyl,n-pentyl, n-hexyl, n-heptyl, and n-octyl groups. Examples of branchedalkyl groups include, but are not limited to, isopropyl, sec-butyl,t-butyl, neopentyl, and isopentyl groups. Representative substitutedalkyl groups may be substituted one or more times with, for example,amino, thio, hydroxy, cyano, alkoxy, and/or halo groups such as F, Cl,Br, and I groups. As used herein the term haloalkyl is an alkyl grouphaving one or more halo groups. In some embodiments, haloalkyl refers toa per-haloalkyl group.

Cycloalkyl groups are cyclic alkyl groups such as, but not limited to,cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cycloheptyl, andcyclooctyl groups. In some embodiments, the cycloalkyl group has 3 to 8ring members, whereas in other embodiments the number of ring carbonatoms range from 3 to 5, 6, or 7. Cycloalkyl groups may be substitutedor unsubstituted. Cycloalkyl groups further include polycycliccycloalkyl groups such as, but not limited to, norbornyl, adamantyl,bornyl, camphenyl, isocamphenyl, and carenyl groups, and fused ringssuch as, but not limited to, decalinyl, and the like. Cycloalkyl groupsalso include rings that are substituted with straight or branched chainalkyl groups as defined above. Representative substituted cycloalkylgroups may be mono-substituted or substituted more than once, such as,but not limited to: 2,2-; 2,3-; 2,4-; 2,5-; or 2,6-disubstitutedcyclohexyl groups or mono-, di-, or tri-substituted norbornyl orcycloheptyl groups, which may be substituted with, for example, alkyl,alkoxy, amino, thio, hydroxy, cyano, and/or halo groups.

Alkenyl groups are straight chain, branched or cyclic alkyl groupshaving 2 to about 20 carbon atoms, and further including at least onedouble bond. In some embodiments alkenyl groups have from 1 to 12carbons, or, typically, from 1 to 8 carbon atoms. Alkenyl groups may besubstituted or unsubstituted. Alkenyl groups include, for instance,vinyl, propenyl, 2-butenyl, 3-butenyl, isobutenyl, cyclohexenyl,cyclopentenyl, cyclohexadienyl, butadienyl, pentadienyl, and hexadienylgroups among others. Alkenyl groups may be substituted similarly toalkyl groups. Divalent alkenyl groups, i.e., alkenyl groups with twopoints of attachment, include, but are not limited to, CH—CH═CH₂, C═CH₂,or C═CHCH₃.

As used herein, “aryl”, or “aromatic,” groups are cyclic aromatichydrocarbons that do not contain heteroatoms. Aryl groups includemonocyclic, bicyclic and polycyclic ring systems. Thus, aryl groupsinclude, but are not limited to, phenyl, azulenyl, heptalenyl,biphenylenyl, indacenyl, fluorenyl, phenanthrenyl, triphenylenyl,pyrenyl, naphthacenyl, chrysenyl, biphenyl, anthracenyl, indenyl,indanyl, pentalenyl, and naphthyl groups. In some embodiments, arylgroups contain 6-14 carbons, and in others from 6 to 12 or even 6-10carbon atoms in the ring portions of the groups. The phrase “arylgroups” includes groups containing fused rings, such as fusedaromatic-aliphatic ring systems (e.g., indanyl, tetrahydronaphthyl, andthe like). Aryl groups may be substituted or unsubstituted.

Electrochromic, solution phase devices are provided having a narrow cellspacing dimension that is less than 65 and for which collapse of thecell spacing is prevented by non-dissolving, in-view spacing objects.The non-dissolving, in-view spacing objects are minimally, or are not,visible to the naked eye when the electrochromic device is in the low-and high-transmission states, or when the electrochromic device is in atransitioning state between the low- and high-transmission states, andthe in-view spacing objects do not detract from the aesthetic appearanceof the device. Further, the narrow cell spacing provides for fastercoloring and clearing times in the devices.

As used herein, the term “in-view” is intended to refer to the use ofthe spacing objects in the field of view of the electrochromic device.For example, where the device is a mirror, the spacing objects are inthe viewing field of the mirror, or where the device is a window, thespacing objects are in the viewing field of the window. By reference tothe naked eye, it will be appreciated that under normal, unaided viewingof the device a person will not detect, or will not perceive anydetraction from, the spacing objects. If the spacing objects are of suchsmall dimensions that they are not visible under normal viewing, theobjects may be colored, opaque, or colored and opaque. Where the spacingobjects are of a dimension that may be otherwise detected by the nakedeye, they may be made of a colorless, a transparent, or both a colorlessand transparent material.

Provided herein are electrochromic devices having a narrow cell spacingwith in-view, insoluble spacing objects to prevent collapse of the cellduring back filling of the electrochromic device, and which may assistin maintaining the cell spacing during normal use and operation of thedevice. The cell spacing is sufficiently small such that the insolublebeads are not readily observed and/or do not distract from the overallaesthetic appearance of the device in any transmission state of thedevice. Additionally, for thin substrates (e.g. 0.7 mm, 0.5 mm, 0.3 mm,or 0.003 mm glass or plastic, or any value or range in between suchvalues), or for larger devices where sagging of a polymer gel within themedium may cause non-uniform cell spacing, in-view insoluble spacingobjects may be used to maintain the cell spacing during filling or useof the device.

Accordingly, in one aspect, an electrochromic the device includes achamber defined by a substantially transparent first substrate, a secondsubstrate, and a sealing member, where a second surface of the firstsubstrate proximal to a first surface of the second substrate aresubstantially uniformly spaced apart from one another by a distance, d.According to some embodiments, d is greater than 0 μm and less than orequal to 65 μm. This includes, but is not limited to the following dvalues: 0<d≦60 μm, 0<d≦55 μm, 0<d≦45 μm, 10<d≦65 μm, 10<d≦55 μm, and10<d≦45 μm. Within the chamber are disposed insoluble spacing objects tomaintain the separation of the second surface of the first substrate andthe first surface of the second substrate.

The insoluble spacing objects include a colorless material, atransparent material, or a colorless and transparent material. Theinsoluble spacing objects may be a ceramic, a polymer that is insolublein the solvent, a glass, a metal oxide, an insoluble salt, or anon-conductive object. The insoluble spacing objects have a largestdimension that is greater than 0, but less than or equal to d. Accordingto any of the embodiments, d may be from greater than 0 μm to less thanor equal to 65 from greater than 0 μm to less than or equal to 55 fromgreater than 0 μm to less than or equal to 45 from greater than 10 μm toless than or equal to 40 from greater than 10 μm to less than or equalto 25 from greater than 5 μm to less than or equal to 30 from greaterthan 5 μm to less than or equal to 25 or from greater than 5 μm to lessthan or equal to 20 In some embodiments, d may be from greater than 10μm to less than or equal to 35 from greater than 20 μm to less than orequal to 40 or about 30 In any of the above embodiments, the insolublespacing objects may be substantially transparent to the naked eye in thedevice, independent of the transmission state in which the device ispoised. The shape of the insoluble spacing objects is not particlularlylimited with the objects taking the form of beads, rods, cubes, and thelike. In some embodiments, the objects are beads. The density, i.e.number of beads per square centimeter, of the beads in the cell may beregulated. Too few beads and the cell spacing may collapse, too many anda haze may be imparted to the device. The density of the beads isdevice-specific and may vary across a wide range. However, the densityof beads may range from, in some embodiments, from 2 beads/cm² to 100beads/cm². This may include, but is not limited to, 5 beads/cm² to 50beads/cm², and 10 beads/cm² to 30 beads/cm².

The insoluble spacing objects may also have a refractive index that isclosely matched to the refractive index of the electrochromic medium tominimize observation of the spacing objects with the naked eye. Therefractive index of the bead may vary from the refractive index of theelectrochromic medium by less than 20%, according to some embodiments.This may include a difference of less than 15%, less than 10%, less than8%, or less than 5%. The refractive index of the objects may be modifiedusing a variety of coatings on the object, or the refractive index ofthe medium may be modified to more closely match that of the objects.

The first substrate includes a first surface, and the second surfaceopposite to the first surface. The second surface includes a firstsubstantially transparent, electrically conductive coating. The secondsubstrate includes the first surface that has a electrically conductivecoating, and is located opposite to a second surface. The electricallyconductive coating of the second substrate may be a transparent,transflective, or reflective coating, or the second substrate may be aconductive material such as a metal.

Disposed within the chamber is an electrochromic medium. The mediumincludes a cathodic component, an anodic component, and a solvent. Theanodic and cathodic components may exhibit slow diffusion throughout theelectrochromic medium to allow for the small cell spacing devices (i.e.those having a value of d from greater than 0 μm to equal to or lessthan 65 μm, or as otherwise set forth above) to color to center without,or with only mimimal, irising of the device. As used herein, “irising”refers to the tendency of an electrochromic device under variousconditions to color at the edges of the device to a greater extent thatin the center of the device upon application of an electric field.

Typically both the anodic and cathodic materials are electroactive andat least one of them is electrochromic. It will be understood thatregardless of its ordinary meaning, the term “electroactive” will bedefined herein as a material that undergoes a modification in itsoxidation state upon exposure to a particular electrical potentialdifference. Additionally, it will be understood that the term“electrochromic” will be defined herein, regardless of its ordinarymeaning, as a material that exhibits a change in its extinctioncoefficient at one or more wavelengths upon exposure to a particularelectrical potential difference, and the wavelength may be in theinfrared, visible, or ultraviolet.

The electrochromic materials may include those having a low diffusioncoefficient. Such materials exhibit lower mobility within theelectrochromic medium. Illustrative, low diffusion coefficients may befrom, but are not limited to, about 1×10⁻⁶ to about 4×10⁻⁶ cm/second².This may include from about 1×10⁻⁶ to about 2×10⁻⁶ cm/second². Inaddition to the cathodic and anodic materials described herein, otherillustrative cathodic and anodic materials are generally andspecifically described by U.S. Pat. Nos. 6,710,906 and 6,525,861, whichare incorporated herein by reference.

Illustrative cathodic materials include reducible species. Illustrativecathodic materials may include, but are not limited to, viologen andmetallocinium compounds. For example, illustrative viologens include,but are not limited to, those as described by Formula (I):

In Formula (I), R¹ and R² may be individually alkyl, siloxyalkyl,hydroxyalkyl, carboxyalkyl, phosphonylalkyl, alkenyl, or aralkyl; R⁴,R⁶, R⁸, and R¹⁰ may be individually H, OR²⁰, F, Cl, Br, I, CN, NO₂,alkyl, or aryl; R²⁰ is H or alkyl; and X is an anion. Also in Formula I,R³, R⁵, R⁷, and R⁹ may individually be H, OR²⁰, F, Cl, Br, I, CN, NO₂,alkyl, or aryl. In some embodiments, R¹ and/or R² are links to a polymerbackbone, such that the viologen is tied into the polymer backbone, orR¹ and/or R² are bridging groups between other Formula (I) compounds. Asdiscussed previously in defining the terms, the alkyl, siloxyalkyl,hydroxyalkyl, carboxyalkyl, phosphonylalkyl, alkenyl, or aralkyl of R¹and R² may be substituted or unsubstituted. Substitution may includesolubilizing groups such as ammonium groups, phosphonium groups,pyridinium groups, or other solubility enhancing groups as described inU.S. Pat. No. 6,445,486. When the R¹ and R² of Formula (I) aresubstituted with such solubilizing groups, it may be R⁴, R⁶, R⁸, and R¹⁰are H. Any of R¹-R¹⁰ may be substituted with ammoniumalkyl(-alkyl[NR′₃]⁺), where each R′ is individually selected from H oralkyl), phosphoniumalkyl (alkyl[PR′₃]⁺), where each R′ is individuallyselected from H, alkyl, or aryl), ether, or ester functionality to aidin achieving higher concentration cathodic materials in theelectrochromic medium.

X is an anion that may be, but is not limited to, a halide, a borate, afluoroborate, a tetraaryl borate, a hexafluoro metal or metalloid, asulfate, a sulfonate, a sulfonamide, a carboxylate, a perchlorate, atetrachloroferrate, or the like. Illustrative X groups include, but arenot limited to: F⁻, Cl⁻, Br⁻, I⁻, BF₄ ⁻, PF₆ ⁻, SbF₆ ⁻, AsF₆ ⁻, ClO₄ ⁻,SO₃CF₃ ⁻, N(CN)₂ ⁻, N(CF₃SO₂)₂ ⁻, C(CF₃SO₂)₃ ⁻, N(SO₂C₂F₅)₂ ⁻,⁻Al(OC(CF₃)₃)₄ or ⁻BAr₄, wherein Ar is a aryl or fluorinated aryl group.In one embodiment, X⁻ is ⁻BAr₄ and Ar is a pentafluorophenyl group. Insome embodiments, X is a tetrafluoroborate or abis(trifluoromethylsulfonyl) imide anion. When shown in any compoundherein multiple X's may be a mixture of two or more such anions.

R¹ and R² may be individually a C₁-C₁₂ alkyl group that is substitutedor unsubstituted, or which may be further connected to an aryl group,cyclic group, heterocyclic group, or heteroaryl group. In someembodiments, R¹ and R² are individually a C₁-C₁₂ alkyl group substitutedwith a silyloxy or a hydroxyl group at the end. In some embodiments, R¹and R² are individually a hydroxyalkyl group. In some embodiments, R¹ isa hydroxypentanyl group. In some embodiments, R² is a hydroxyundecanylgroup.

R⁴, R⁶, R⁸, and R¹⁰ may be individually H, OH, or alkyl. In someembodiments, R⁴, R⁶, R⁸, and R¹⁰ are individually H. In someembodiments, R⁴, R⁶, R⁸, and R¹⁰ are individually C₁-C₆ alkyl. In someembodiments, R⁴, R⁶, R⁸, and R¹⁰ are all H.

R³, R⁵, R⁷, and R⁹ may be individually H, alkyl, or aryl, with theproviso that R³ and R⁵, or R⁷ and R⁹, or R³ and R⁵ and R⁷ and R⁹ areindividually secondary alkyl, tertiary alkyl, or aryl. In someembodiments, R³, R⁵, R⁷, and R⁹ are individually secondary or tertiaryC₃-C₁₂ alkyl. In some embodiments, R³, R⁵, R⁷, and R⁹ are individually Hor aryl. In some embodiments, R³ and R⁵ are individually secondaryalkyl, tertiary alkyl, or aryl. In some embodiments, R³ and R⁵ areindividually aryl. In some embodiments, R³ and R⁵ are aryl and R⁷ and R⁹are H.

In the above embodiments, R³, R⁵, R⁷, or R⁹ may be an aryl group ofFormula (II):

In Formula (II), R¹¹, R¹², R¹³, and R¹⁴ may be individually H, OR²⁰, F,Cl, Br, I, CN, NO₂, or alkyl; R¹⁵ is H, OH, F, Cl, Br, I, CN, NO₂,—OC(O)NR¹⁶R¹⁷, alkyl, or alkoxy; R¹⁶ is H or alkyl; R²⁰ is H or alkyl;and R¹⁷ is H, alkyl or siloxy alkyl.

In some embodiments, in Formula (II), R¹¹, R¹², R¹³, and R¹⁴ may beindividually H or alkyl. In some embodiments, R¹¹, R¹², R¹³, and R¹⁴ areindividually H or C₁-C₆ alkyl. In some embodiments, R¹¹, R¹², R¹³, andR¹⁴ are all H. In some embodiments, R¹⁵ is H, OH, alkyl, or alkoxy. Insome embodiments, R¹⁵ is C₁-C₆ alkyl. In some embodiments, R¹⁵ is H,methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl, or tert-butyl. Insome embodiments, R¹¹, R¹², R¹³, and R¹⁴ are H, and R¹⁵ is H, methyl,ethyl, propyl, iso-propyl, butyl, sec-butyl, or tert-butyl. In someembodiments, R¹⁶ is H. In other embodiments, R¹⁶ is C₁-C₆ alkyl. In someembodiments, R¹⁷ is alkyl or siloxy alkyl. In some embodiments, R¹⁷ isH, methyl, ethyl, propyl, iso-propyl, butyl, sec-butyl, tert-butyl, or—(CH₂)_(n)Si(OR¹⁸)₃, R¹⁸H or alkyl, and n is 1 to 10.

Alternatively in Formula (I), R¹ and R² may be individually alkyl orhydroxyalkyl, and R³ and R⁵, or R⁷ and R⁹, may be individually an arylof Formula (II). In some embodiments, R³ and R⁵ are an aryl group. Insome embodiments, R⁷ and R⁹ are an aryl group. In some embodiments, R³and R⁵, or R⁷ and R⁹, are a phenyl. In some embodiments, R³, R⁵, R³ andR⁹ are each an aryl group of Formula (II). In some embodiments, R¹¹,R¹², R¹³, and R¹⁴ are H, and R¹⁵ is H, OH, alkyl or alkoxy. In someembodiments, R¹¹, R¹², R¹³, and R¹⁴ are H, and R¹⁵ is H, OH, Me, ormethoxy.

In one embodiment, for a compound of Formula (I), R¹ and R² areindividually an alkyl group, and R³ and R⁵, or R⁷ and R⁹, areindividually aryl of Formula (II). In some embodiments, R³ and R⁵, or R⁷and R⁹, may be substituted phenyl. In some embodiments, R³ and R⁵, or R⁷and R⁹, may be phenyl substituted with a carbamate group. In someembodiments, R³ and R⁵, is each an aryl of Formula (II). In otherembodiments, R⁷ and R⁹, may each be an aryl of Formula (II). In someembodiments, R¹¹, R¹², R¹³, and R¹⁴ are H, and R¹⁵ is —OC(O)NR¹⁶R¹⁷. Insome embodiments, R¹⁶ is H. In some embodiments, R¹⁷ is alkyl or siloxyalkyl. In some embodiments, R¹⁷ is —(CH₂)_(n)Si(OR¹⁸)₃, R¹⁸H or alkyl,and n is 1 to 10. In some embodiments, R¹⁷ is —(CH₂)_(n)Si(OR¹⁸)₃, R¹⁸is methyl or ethyl, and n is 3.

In one aspect, the viologen is represented by Formula (III)

In Formula (III), R¹⁹ is (CH₂)_(n′) or arylene, and n′ is from 1 to 12.

For compounds of Formula (III), R¹-R¹⁰, and X are as defined herein forFormula (I). In some embodiments, R¹⁹ is (CH₂)_(n′) wherein n′ is from1-10. In some embodiments, R¹⁹ is (CH₂)₃₋₈. In other embodiments, R¹⁹ isphenylene. In some embodiments, R¹⁹ is 1,4-phenylene.

Alternatively in Formula (III), R¹ and R² may be individually alkyl orhydroxyalkyl, and R³ and R⁵, or R⁷ and R⁹, may be individually an arylof Formula (II). In some embodiments, R³ and R⁵ are an aryl group. Insome embodiments, R⁷ and R⁹ are an aryl group. In some embodiments, R¹¹,R¹², R¹³, and R¹⁴ are H, and R¹⁵ is H, OH, alkyl, or alkoxy. In someembodiments, R¹¹, R¹², R¹³, and R¹⁴ are H, and R¹⁵ is methyl. In someembodiments, R¹¹, R¹², R¹³, and R¹⁴ are H, and R¹⁵ is H, OH, Me, ormethoxy. In some embodiments, R¹⁹ is (CH₂)_(n′) wherein n′ is from 1-10.In some embodiments, R¹⁹ is 1,4-phenylene.

In some embodiments, for a compound of Formula (III), R¹ and R² areindividually methyl, R³ and R⁵ are each an aryl of Formula (II), R¹¹,R¹², R¹³, and R¹⁴ are H, R¹⁵ is H, OH, Me, or methoxy, and R¹⁹ is(CH₂)_(n′) wherein n′ is from 1-10.

In some embodiments, for a compound of Formula (III), R¹ and R² areindividually alkyl or hydroxyalkyl, R⁷ and R⁹ are each an aryl ofFormula (II), R¹¹, R¹², R¹³, and R¹⁴ are H, and R¹⁵ is methyl, and R¹⁹is 1,4-phenylene.

In some embodiments, for a compound of Formula (III), R¹ and R² areindividually alkyl or hydroxyalkyl, R⁷ and R⁹ are each an aryl ofFormula (II), R¹¹, R¹², R¹³, and R¹⁴ are H, and R¹⁵ is methyl, and R¹⁹is (CH₂)_(n′) wherein n′ is 3.

In another aspect, the viologen is represented by Formula (IV)

In Formula (IV), R¹ and R^(1′) may be individually alkyl, ammoniumalkyl,phosphoniumalkyl, siloxyalkyl, hydroxyalkyl, alkylcarboxylate,alkylphosphonate, alkylisocyanate, carboxylate, phosphonate, isocyanate,alkenyl, or aralkyl; R⁴, R⁶, R⁸, R¹⁰, R^(4′), R^(6′), R^(8′), andR^(10′) may be individually H, OR²⁰, F, Cl, Br, I, CN, NO₂, alkyl,oraryl; and R³, R⁵, R⁷, R⁹, R^(3′), R^(5′), R^(7′), and R^(9′) may beindividually H, OR²⁰, F, Cl, Br, I, CN, NO₂, alkyl, or aryl, with theproviso that R³, R⁵, R^(3′), and R^(5′) are individually secondaryalkyl, tertiary alkyl, or aryl; and R¹⁹ is (CH₂)_(n′) or arylene, R²⁰ isH or alkyl, and n′ is from 1 to 12. X is an anion as defined above.

The compound of Formula (IV) includes where R¹ and R^(1′) may beindividually alkyl, siloxyalkyl, hydroxyalkyl, alkylcarboxylate,alkylphosphonate, alkylisocyanate, alkenyl, or aralkyl; R⁴, R⁶, R⁸, R¹⁰,R^(4′), R^(6′), R^(8′), and R^(10′) may be individually H, OH, F, Cl,Br, I, CN, NO₂, alkyl, or aryl; and R³, R⁵, R⁷, R⁹, R^(3′), R^(5′),R^(7′), and R^(9′) may be individually H, OH, F, Cl, Br, I, CN, NO₂,alkyl, or aryl, with the proviso that R⁷, R⁹, R^(7′), and R^(9′) areindividually secondary alkyl, tertiary alkyl, or aryl; R¹⁹ is (CH₂)_(n′)or arylene, and n′ is from 1 to 12. X is an anion as defined above.

In another aspect, the viologen is represented by Formula (V)

In Formula (V), R¹ and R^(1′) are individually —(CH₂)_(n)OH,—(CH₂)_(n)Br, —(CH₂)_(n)Cl, —(CH₂)_(n)Si(OH)₃, —(CH₂)_(n)Si(OMe)₃,—(CH₂)_(n)Si(OEt)₃,

—(CH₂)_(n)CH═CH₂, —(CH₂)_(n)COC(O)CH═CH₂, or —(CH₂)_(n)COC(O)C(CH₃)═CH₂;R²⁵ and R²⁶ are individually H, Me, Et, Pr, OMe, OEt, OPr,OC(O)(CH₂)_(n)Si(OH)₃, OC(O)(CH₂)_(n)Si(OMe)₃, OC(O)NH(CH₂)_(n)Si(OEt)₃,OC(O)NH(CH₂)_(n)COOH, OC(O)NH(CH₂)_(n)P(O)(OH)₂, or OC(O)NH(CH₂)_(n)NCO;and n is 1 to 12.

In some embodiments, for compounds of Formula (V), R¹ and R^(1′) areindividually —(CH₂)_(n)OH, —(CH₂)_(n)Si(OH)₃, —(CH₂)_(n)Si(OMe)₃,—(CH₂)_(n)Si(OEt)₃,

—(CH₂)_(n)CH═CH₂, —(CH₂)_(n)COC(O)CH═CH₂, or —(CH₂)_(n)COC(O)C(CH₃)═CH₂.In some embodiments, for compounds of Formula (V), R¹ and R^(1′) areeach —(CH₂)_(n)OH, wherein n=1 to 15. In some embodiments, for compoundsof Formula (V), R²⁵ and R²⁶ are each OC(O)NH(CH₂)_(n)Si(OEt)₃; and n is1 to 12.

Illustrative anodic materials include oxidizable species. Illustrativeanodic materials may include, but are not limited to, metallocenes,5,10-dihydrophenazines, phenothiazines, phenoxazines, carbazoles,triphenodithiazines, triphendioxazines, and related compounds. Anodicmaterials included in the electrochromic medium may include any one of anumber of materials including ferrocene, substituted ferrocenes,substituted ferrocenyl salts, phenazine, substituted phenazines,phenothiazine, substituted phenothiazines, including substituteddithiazines, thianthrene, and substituted thianthrenes. Examples ofanodic materials may include di-tert-butyl-diethylferrocene,5,10-dimethyl-5,10-dihydrophenazine (DMP),3,7,10-trimethylphenothiazine, 2,3,7,8-tetramethoxy-thianthrene,10-methylphenothiazine, tetramethylphenazine (TMP),bis(butyltriethylammonium)-para-methoxytriphenodithiazine (TPDT), and3,10-dimethoxy-7,14-(triethylammoniumbutyl)-triphenodithazinebis(tetrafluoroborate).Any of the anodic materials may be substituted with alkylammonium(-alkyl[NR′₃]⁺, where each R′ is individually selected from H or alkyl),alkylphosphonium (-alkyl[PR′₃]⁺, where each R′ is individually selectedfrom H, alkyl, or aryl), ether, or ester functionality to aid inachieving higher concentration anodic materials in the electrochromicmedium. In some embodiments, the anodic material is substituted withalkylammonium or alkylphosphonium.

In some embodiments, a solvent of the electrochromic medium may include,but is not limited to, 3-methylsulfolane, dimethyl sulfoxide, dimethylformamide, tetraglyme and other polyethers; alcohols such asethoxyethanol; nitriles, such as acetonitrile, glutaronitrile,3-hydroxypropionitrile, and 2-methylglutaronitrile; ketones including2-acetylbutyrolactone, and cyclopentanone; cyclic esters includingbeta-propiolactone, γ-butyrolactone, γ-valerolactone; propylenecarbonate (PC), ethylene carbonate; oligoethers; ionic liquids, such aspyridinium-, imidazolium-, and pyrrolidinium-compounds; and homogenousmixtures of any two or more such solvents. Where the solvent includes anionic liquid, the counterion may be F⁻, Cl⁻, Br⁻, I⁻, BF₄ ⁻, PF₆ ⁻, SbF₆⁻, AsF₆ ⁻, ClO₄ ⁻, SO₃CF₃ ⁻, N(CN)_(z) ⁻, N(CF₃SO₂)₂ ⁻, C(CF₃SO₂)₃ ⁻,N(SO₂C₂F₅)⁻, ⁻Al(OC(CF₃)₃)₄ or ⁻BAr₄ where Ar is a aryl or fluorinatedaryl group, or other counterions used in ionic liquids. In oneembodiment, the counterion ⁻ is BAr₄ and Ar is a pentafluorophenylgroup. In another embodiment, the electrochromic composition may includea solvent that includes propylene carbonate. While specific solventshave been disclosed as being associated with the electrochromiccomposition, numerous other solvents that would be known to those havingordinary skill in the art having the present disclosure before them arelikewise contemplated for use. For example, in addition to the solvent,the electrochromic medium may be a gel composition.

In addition, the electrochromic medium may include other materials, suchas light absorbers, reducing compounds, light stabilizers, thermalstabilizers, antioxidants, oxygen scavengers, thickeners, viscositymodifiers, tint providing agents, redox buffers, and mixtures of any twoor more such materials. Illustrative UV-stabilizers may include, but arenot limited to, 2-ethyl-2-cyano-3,3-diphenyl acrylate;(2-ethylhexyl)-2-cyano-3,3-diphenyl acrylate;2-(2′-hydroxy-4′-methylphenyl)benzotriazole, sold by Ciba-Geigy Corp.under the trademark Tinuvin P;3-[3-(2H-benzotriazole-2-yl)-5-(1,1-dimethylethyl)-4-hydroxyphenyl]propionicacid pentyl ester prepared from Tinuvin 213, sold by Ciba-Geigy Corp.,via conventional hydrolysis followed by conventional esterification(hereinafter “Tinuvin PE”); 2,4-dihydroxybenzophenone;2-hydroxy-4-methoxybenzophenone; and 2-ethyl-2′-ethoxyalanilide.Illustrative reducing compounds may include hydroquinones such as, butnot limited to, tetramethylhydroquinone.

In one embodiment, the electrochromic medium further includes an anodicand/or cathodic color-stabilizing redox buffer. Suitable redox buffersinclude, among others, those disclosed in U.S. Pat. No. 6,188,505. Otherexamples of suitable anodic and cathodic redox buffers include, but arenot limited to, metallocene (e.g., substituted ferrocenes), andmetallocinium (e.g. ferrocinium) compounds.

In one embodiment, the electrochromic medium may further include across-linked polymer matrix, a free-standing gel, and/or a substantiallynon-weeping gel.

A schematic representation of an electrochromic device is shown inFIG. 1. The electrochromic device 100 includes first substrate 112having a first surface 112B and a second surface 112A and, and a secondsubstrate 114 having a first surface 114A and a second surface 114B. Thesecond surface 112A and the first surface 114A, separated by distance,d, have associated therewith conductive surfaces 118 and 120,respectively. The first substrate 112 and the second substrate 114,along with a sealing member 122 define a chamber 116 for containing anelectrochromic medium 124. The device also includes one or more plugs126 and 130 associated with one or more fill ports 128. Alternatively,the plugs and fill ports may be through sealing member 122 instead ofsubstrate 112 or substrate 114. The one or more fill ports 128 may bedisposed within the first substrate 112, the second substrate 114, orthe sealing member 122. Upon mounting as a mirror, window, or otherdevice, the electrochromic device 100 may optionally include a bezelthat extends around a periphery of at least one of the first substrate112 and the second substrate 114 to conceal and/or protect a busconnector (if present), the sealing member 122 one or more plugs 126 and130, and the one or more fill ports 128.

Several other electrochromic device configurations are contemplated foruse, including, but not limited to, those disclosed in U.S. Pat. Nos.5,818,625; 6,597,489; and 6,700,692, all of which are herebyincorporated herein by reference to the extent the descriptions thereindo not conflict with the embodiments set forth herein.

In some embodiments, the first substrate may be fabricated from any oneof a number of materials that are transparent or substantiallytransparent in the visible region of the electromagnetic spectrum, suchas, for example, borosilicate glass, soda lime glass, natural andsynthetic polymeric resins, plastics, and/or composites includingpolyesters (e.g. PET), polyimides (PI), polycarbonates, polysulfones,polyethylene naphthalate (PEN), ethylene vinyl acetate (EVA), acrylatepolymers, as well as Topas®. In another embodiment, the first substrateis fabricated from a sheet of glass having a thickness ranging fromabout 0.001 millimeters (mm) to about 12.7 mm. This may include anyrange of thickness such as from about 0.01 mm to about 1.50 mm, or fromabout 0.03 mm to about 1.00 mm. Of course, the thickness of thesubstrate will depend upon the particular application of theelectrochromic device. While particular substrate materials have beendisclosed, for illustrative purposes only, it will be understood thatnumerous other substrate materials are likewise contemplated for use—solong as the materials are at least substantially transparent and exhibitappropriate physical properties, such as strength, to be able to operateeffectively in conditions of intended use. Indeed, electrochromicdevices in accordance with the present invention can be, during normaloperation, exposed to extreme temperature variation as well assubstantial UV radiation, emanating primarily from the sun. It will befurther understood that first substrate and/or second substrate maycomprise a UV absorbing layer and/or contain a UV absorbing material tohelp protect the substrate(s) and/or the electrochromic media from UVdamage.

In some embodiments, the second substrate may be fabricated from similarmaterials as that of the first substrate, however, the conductivecoating on the substrate need not be transparent. For example, thecoating may be transparent, transflective, or reflective. As usedherein, “transflective” describes a material or component that has auseful non-zero level of transmittance and also has a useful, non-zerolevel of reflectance in a specified spectral region. In the context ofan image-forming reflector, such as a mirror for viewing reflectedimages, for example, the viewer in front of the mirror may not onlyobserve an image of the ambient objects, formed in reflection from suchtransflective area but also receive information contained in thedisplayed image delivered with light from the light source locatedbehind the transflective area of the mirror. In some embodiments, wheretransparency of the second substrate is not desired, the secondsubstrate may be a metal. The second substrate may be fabricated from asheet of glass, metal, or plastic having a thickness ranging from about0.001 mm to about 12.7 mm. This may include thicknesses from about 0.03mm to about 1.50 mm, or from about 0.65 mm to about 1.00 mm. If thefirst and second substrates are fabricated from sheets of glass, thenthe glass can, optionally, be tempered, heat strengthened, chemicallystrengthened, and/or laminated prior to or subsequent to being coatedwith layers of electrically conductive material.

One or more layers of electrically conductive material may be associatedwith the rear surface of the first substrate. These layers serve as anelectrode for the electrochromic device. Electrically conductivematerial is desirably a material that: (a) is substantially transparentin the visible region of the electromagnetic spectrum; (b) bondsreasonably well to the first substrate; (c) maintains this bond whenassociated with a sealing member; (d) is generally resistant tocorrosion from materials contained within the electrochromic device orthe atmosphere; and (e) exhibits minimal diffuse or specular reflectanceas well as sufficient electrical conductance. It is contemplated thatthe electrically conductive material may be fabricated from fluorinedoped tin oxide (FTO), for example TEC glass, indium/tin oxide (ITO),doped zinc oxide, indium zinc oxide, metal oxide/metal/metal oxide(wherein metal oxide can be substituted with metal carbide, metalnitride, metal sulfide, etc.), or other materials known to those havingordinary skill in the art.

One or more layers of an electrically conductive material made of thesame or different materials as those associated with the rear surface ofthe first substrate may be associated the front surface of the secondsubstrate. The electrically conductive material may be operativelybonded to electrically conductive material associate with the firstsubstrate by a sealing member. Once bonded, the sealing member, plugand/or the juxtaposed portions of electrically conductive materials mayserve to generally define an inner peripheral geometry of a chamber.Alternatively, edge sealing techniques may be utilized which aredisclosed in U.S. Pat. No. 7,372,611.

In some embodiments, the first substantially transparent substrate andsecond substantially transparent substrate have a cell distance of lessthan 65 μm. In another embodiment, the first substantially transparentsubstrate and second substantially transparent substrate have a celldistance of about 5 μm to about 65 μm, about 10 μm to about 65 μm, about5 μm to about 55 μm, or ranges between any two of these values(including endpoints). In another embodiment, the first substantiallytransparent substrate and second substantially transparent substratehave a cell distance of about 1 μm to about 50 μm, in 0.2 μm increments.

In some embodiments, the sealing member may include any material that isconfigured to adhesively bond to the electrically conductive materialscoated on the first and second substrate to, in turn, seal a chamber,(in certain embodiments in cooperation with a plug and fill port so thatelectrochromic composition does not inadvertently leak out of thechamber. It is also contemplated that the sealing member extends all theway to rear surface and front surface of their respective substrates. Insuch an embodiment, the layers of electrically conductive materialcoated on the first and second substrates may be partially removed wherethe sealing member is positioned. If the electrically conductivematerials are not associated with their respective substrates, then thesealing member preferably bonds well to glass. It will be understoodthat sealing member can be fabricated from any one of a number ofmaterials including, for example, those disclosed in U.S. Pat. Nos.4,297,401; 4,418,102; 4,695,490; 5,596,023; 5,596,024; 6,157,480; and6,714,334.

The concentration of the electrochromic materials in the medium may alsobe modified. As the cell spacing decreases, higher concentrations may beused to maintain or increase coloration of the device. In someembodiments, the concentration of the anodic and/or cathodic materialsin the electrochromic medium may be from about 1 millimolar (mM) toabout 500 mM. In some embodiments, the concentration of the anodicand/or cathodic materials in the electrochromic medium may be from about2 mM to about 100 mM.

In one embodiment, at least one of the anodic electroactive materialshas a concentration of at least 2 mM. In another embodiment, at leastone of the anodic electroactive materials has a concentration of about 2mM to about 100 mM, about 3 mM to about 70 mM, about 3 mM to about 60mM, or ranges between any two of these values (including endpoints). Inanother embodiment, at least one of the anodic electroactive materialshas a concentration of about 2 mM to about 8 mM. In another embodiment,a second anodic electroactive material has a concentration of about 40mM to about 70 mM.

In one embodiment, at least one of the cathodic electroactive materialshas a concentration of at least 50 mM. In another embodiment, at leastone of the cathodic electroactive materials has a concentration of about50 mM to about 100 mM, about 60 to about 90 mM, about 70 mM to about 80mM, or ranges between any two of these values (including endpoints).

Illustrative electrochromic devices employing the electrochromiccompounds described herein may include, for illustrative purposes only,a window, an aircraft transparency, a mirror, an electromagnetic filter,a display device, and the like. It will be understood that like oranalogous elements and/or components, and/or methods referred to herein,may be identified throughout the drawings with like referencecharacters. In some embodiments, the electrochromic device is anelectrochromic window or an electrochromic mirror. In some embodiments,the device is a vehicular interior electrochromic mirror. In someembodiments, the device is a variable transmission electrochromicwindow. In some embodiments, the device is an aircraft window system.Other applications of the electrochromic device includes screens forwatches, calculators and computer display screens; eye wear such aseyeglasses and sunglasses; switchable mirrors, sun visors; automobile,architectural, aircraft, marine, and spacecraft windows; informationdisplay boards and digital billboards and the like.

EQUIVALENTS

While certain embodiments have been illustrated and described, it shouldbe understood that changes and modifications can be made therein inaccordance with ordinary skill in the art without departing from thetechnology in its broader aspects as defined in the following claims.

The embodiments, illustratively described herein may suitably bepracticed in the absence of any element or elements, limitation orlimitations, not specifically disclosed herein. Thus, for example, theterms “comprising,” “including,” “containing,” etc. shall be readexpansively and without limitation. Additionally, the terms andexpressions employed herein have been used as terms of description andnot of limitation, and there is no intention in the use of such termsand expressions of excluding any equivalents of the features shown anddescribed or portions thereof, but it is recognized that variousmodifications are possible within the scope of the claimed technology.Additionally, the phrase “consisting essentially of” will be understoodto include those elements specifically recited and those additionalelements that do not materially affect the basic and novelcharacteristics of the claimed technology. The phrase “consisting of”excludes any element not specified.

The present disclosure is not to be limited in terms of the particularembodiments described in this application. Many modifications andvariations can be made without departing from its spirit and scope, aswill be apparent to those skilled in the art. Functionally equivalentmethods and compositions within the scope of the disclosure, in additionto those enumerated herein, will be apparent to those skilled in the artfrom the foregoing descriptions. Such modifications and variations areintended to fall within the scope of the appended claims. The presentdisclosure is to be limited only by the terms of the appended claims,along with the full scope of equivalents to which such claims areentitled. It is to be understood that this disclosure is not limited toparticular methods, reagents, compounds compositions or biologicalsystems, which can of course vary. It is also to be understood that theterminology used herein is for the purpose of describing particularembodiments only, and is not intended to be limiting.

In addition, where features or aspects of the disclosure are describedin terms of Markush groups, those skilled in the art will recognize thatthe disclosure is also thereby described in terms of any individualmember or subgroup of members of the Markush group.

As will be understood by one skilled in the art, for any and allpurposes, particularly in terms of providing a written description, allranges disclosed herein also encompass any and all possible subrangesand combinations of subranges thereof. Any listed range can be easilyrecognized as sufficiently describing and enabling the same range beingbroken down into at least equal halves, thirds, quarters, fifths,tenths, etc. As a non-limiting example, each range discussed herein canbe readily broken down into a lower third, middle third and upper third,etc. As will also be understood by one skilled in the art all languagesuch as “up to,” “at least,” “greater than,” “less than,” and the like,include the number recited and refer to ranges which can be subsequentlybroken down into subranges as discussed above. Finally, as will beunderstood by one skilled in the art, a range includes each individualmember.

All publications, patent applications, issued patents, and otherdocuments referred to in this specification are herein incorporated byreference as if each individual publication, patent application, issuedpatent, or other document was specifically and individually indicated tobe incorporated by reference in its entirety. Definitions that arecontained in text incorporated by reference are excluded to the extentthat they contradict definitions in this disclosure.

Other embodiments are set forth in the following claims.

1. An electrochromic device comprising: a chamber defined by asubstantially transparent first substrate, a second substrate, and asealing member; wherein: the first substrate comprises a first surface,and a second surface comprising a first substantially transparent,electrically conductive coating and disposed opposite to the firstsurface; the second substrate comprising a first surface comprising anelectrically conductive coating, and a second surface disposed oppositeto the first surface; the second surface of the first substrate and thefirst surface of the second substrate being located proximally to eachother and having a substantially uniform spacing of distance, d, betweenthem; and 0 μm<d≦65 μm; an electrochromic medium comprising a cathodiccomponent, an anodic component, and a solvent; and insoluble spacingobjects within the chamber, the insoluble spacing objects having alargest dimension that is greater than 0, but less than or equal to d.2. The electrochromic device of claim 1, wherein 5 μm<d≦40 μm.
 3. Theelectrochromic device of claim 2, wherein 10 μm<d≦35 μm.
 4. Theelectrochromic device of claim 1, wherein 30 μm<d≦40 μm.
 5. Theelectrochromic device of claim 1, wherein the insoluble spacing objectscomprise a colorless material, a transparent material, or a colorlessand transparent material.
 6. The electrochromic device of claim 1,wherein the insoluble spacing objects comprise a ceramic or a polymer.7. The electrochromic device of claim 1, wherein the insoluble spacingobjects comprise glass or a metal oxide.
 8. The electrochromic device ofclaim 1, wherein the insoluble spacing objects are substantiallytransparent to the naked eye.
 9. The electrochromic device of claim 1which is a mirror, an architectural window, an aircraft transparency, alens, or a filter.
 10. The electrochromic device of claim 1, wherein thecathodic compound, the anodic compound, or both the cathodic and theanodic compound exhibit a low diffusion coefficient.
 11. Theelectrochromic device of claim 10, wherein low diffusion coefficient isfrom about 1×10⁻⁶ to about 4×10⁻⁶ cm²/second.
 12. The electrochromicdevice of claim 11, wherein low diffusion coefficient is from about1×10⁻⁶ to about 2×10⁻⁶ cm²/second.
 13. The electrochromic device ofclaim 1, wherein the cathodic compound comprises a viologen or ametallocinium.
 14. The electrochromic device of claim 1, wherein theanodic compound comprises a metallocene, a 5,10-dihydrophenazine, aphenothiazine, a phenoxazine, a carbazole, a triphenodithiazine, or atriphendioxazine.
 15. The electrochromic device of claim 1, wherein theelectrochromic medium comprises at least two different anodiccomponents.
 16. The electrochromic device of claim 1, wherein arefractive index of the spacing object is closely matched to arefractive index of the electrochromic medium.
 17. The electrochromicdevice of claim 16, wherein a refractive index of the spacing object anda refractive index of the electrochromic medium differ by no more than20%.
 18. The electrochromic device of claim 17, wherein a refractiveindex of the spacing object and a refractive index of the electrochromicmedium differ by less than 5%.